Field
One or more embodiments relate to a separator and a lithium battery including the separator.
Description of the Related Art
To comply with demand for small and high-performance devices, small and light-weight lithium batteries have been manufactured. Also, for use in electric vehicles, discharging capacity, energy density, and cycle characteristics of lithium batteries are taken into consideration as important factors. For use in such appliances, lithium batteries with large discharge capacity and high energy density per unit volume and excellent lifespan characteristics are required.
A lithium battery includes a separator to prevent short-circuiting between a positive electrode and a negative electrode. An organic separator melts at a temperature of 200° C. or less. Thus, when the temperature of a battery including an organic-based separator is increased due to inner and/or external stimuli, a volumetric change may occur due to shrinking or melting of the separator, thereby stopping operation of the battery.
Olefin-based polymers have been widely used as a separator for lithium batteries. Although a separator comprising an olefin-based polymer has excellent flexibility, strength of the separator decreases after being immersed in an electrolytic solution, and short-circuit may occur due to rapid thermal shrinkage at a high temperature of 100° C. or greater.
Thus, there is a need to develop a separator having high stability due to high heat resistance and low thermal shrinkage.